Part of the problem is the lack of all wheel drive but the main problem seems to be the weight. 4,533 pounds... ouch. The Audi S7 even with its all wheel drive system is about 100 pounds lighter. The X-Drive version of the 650i Gran Coupe balloons to an absurd SUV like 4670 pounds. Efficient Dynamics are at work where again?

Both the Audi S7 and the Mercedes-Benz CLS550 are quicker and faster than the 650i. Both are lighter and even the 4Matic Mercedes-Benz CLS550 is lighter than the rear wheel drive BMW 650i by about 200 pounds. It isn't just Mercedes building lighter and faster cars than BMW, Audi is too, and both of them are even doing it with all wheel drive. Mercedes-Benz doing it with both rear and all wheel options. Something just isn't right in Bavaria.

I hate the fact that the 6-series Gran Coupe is so large and heavy. It looks so good, yet it is a waste of engine power. The automotive industry regulators should impose a 3500lbs limit on cars, this would probably be a very efficient way to reduce overall emissions ad would force manufacturers to put as much emphasis on the weight reduction technologies as they do on the hybrid engines.

I agree with that but the public is hungry for new options especially in this market. More toys = more weight. As far as building cars lighter with the same features will mean more exotic materials and higher prices.